BACKGROUND: Acute respiratory illnesses (ARIs) are common in school-aged children, but few studies have assessed school absenteeism due to specific respiratory viruses. OBJECTIVE: Evaluate school absenteeism among children with medically attended ARI due to common viruses. METHODS: We analyzed follow-up surveys from children seeking care for acute respiratory illness who were enrolled in the influenza vaccine effectiveness study at Marshfield Clinic during the 2012-2013 through 2014-2015 influenza seasons...

INTRODUCTION: Epidemiological studies of the 1957 influenza pandemic are scarce, particularly from lower income settings. METHODS: We analyzed the spatial-temporal mortality patterns of the 1957 influenza pandemic in Chile including detailed age-specific mortality data from a large city and investigated risk factors for severe mortality impact across regions. RESULTS: Chile exhibited two waves of excess mortality in winter 1957 and 1959 with a cumulative excess mortality rate of 12 per 10,000, and a ~10-fold mortality difference across provinces...

BACKGROUND: Guatemala is the country with the largest swine production in Central America; however, evidence of influenza A virus (IAV) in pigs has not been clearly delineated. OBJECTIVES: In this study, we analyzed the presence and spatial distribution of IAV in commercial and backyard swine populations. METHODS: Samples from two nation-wide surveys conducted in 2010 and 2011 were tested using virological (rRT-PCR and virus isolation) and serological (ELISA and Hemagglutination Inhibition) assays to detect IAV...

Trivalent seasonal influenza vaccine effectiveness during the 2015 season in South Africa was assessed using a test-negative case control study design. Influenza A(H1N1)pdm09 was the dominant circulating strain. Overall influenza vaccine coverage was 3.2% (29/899). The vaccine effectiveness estimate, against any influenza virus infection, adjusted for age, underlying conditions and timing within season was 46.2% (95% CI: -23.5% to 76.5%), and 53.6% (95% CI: -62.6% to 80.3%) against influenza A(H1N1)pdm09. This article is protected by copyright...

BACKGROUND: The first human infections of novel avian influenza A(H7N9) virus were identified in China in March 2013. Sentinel surveillance systems and contact tracing may not identify mild and asymptomatic human infections of influenza A(H7N9) virus. OBJECTIVES: We assessed the seroprevalence of antibodies to influenza A(H7N9) virus in three populations during the early stages of the epidemic. PATIENTS/METHODS: From March 2013-May 2014, we collected sera from the general population, poultry workers and contacts of confirmed infections in nine Chinese provinces reporting human A(H7N9) infections and, for contacts, second sera 2-3 weeks later...

BACKGROUND: The total burden of influenza in primary care is difficult to assess. The case definition of medically attended "acute respiratory infection" (MAARI) in the German physician sentinel is sensitive, however it requires modelling techniques to derive estimates of disease attributable to influenza. We aimed to examine the impact of type/subtype and age. METHODS: Data on MAARI and virological results of respiratory samples (virological sentinel) were available from 2001/02 until 2014/15...

BACKGROUND: Following the 2013 USA release of the Influenza Virologic Surveillance Right Size Roadmap, the New York State Department of Health (NYSDOH) embarked on an evaluation of data sources for influenza virologic surveillance. OBJECTIVE: To assess NYS data sources, additional to data generated by the state public health laboratory (PHL), which could enhance influenza surveillance at the state and national level. METHODS: Potential sources of laboratory test data for influenza were analyzed for quantity and quality...

BACKGROUND: National media reported a febrile illness among dormitory residents of a boys' religious school. We investigated the outbreak to identify cause. METHODS: Individuals with fever (>100°F) and cough or sore throat between 1 and 13 August 2011 were influenza-like-illness (ILI) case-patients. We collected histories and specimens from hospitalized case-patients and visited campus to explore environmental context. RESULTS: All 28 case-patients were dormitory residents including 27 hospitalizations...

BACKGROUND: Influenza B is characterised by two antigenic lineages: B/Victoria and B/Yamagata. These lineages circulate together with influenza A during influenza seasons, with varying incidence from year to year and by geographic region. OBJECTIVE: To determine the epidemiology of influenza B relative to influenza A in Australia. METHODS: Laboratory-confirmed influenza notifications between 2001 and 2014 in Australia were obtained from the Australian National Notifiable Diseases Surveillance System...

We previously reported that horse antiserum against the Japanese equine influenza vaccine virus, A/equine/La Plata/1993 (LP93) exhibited reduced cross-neutralization against some Florida sublineage Clade (Fc) 2 viruses, for example, A/equine/Carlow/2011 (CL11). As a result, Japanese vaccine manufacturers will replace LP93 with A/equine/Yokohama/aq13/2010 (Y10, Fc2). To assess the benefit of updating the vaccine, five horses vaccinated with inactivated Y10 vaccine and five vaccinated with inactivated LP93 were challenged by exposure to a nebulized aerosol of CL11...

This manuscript describes the identification of an oseltamivir-resistant influenza A (H3N2) virus in a respiratory specimen collected from an immunocompromised patient in Alberta, Canada, during the 2014-2015 influenza season. Following treatment with oseltamivir, neuraminidase (NA) gene sequencing indicated the presence of an R292K mutation. Phenotypic susceptibility testing by the NA-Star assay indicated a highly reduced inhibition by oseltamivir and normal inhibition by zanamivir. The use of zanamivir following identification of the oseltamivir-resistant strain, combined with a partial immune reconstitution, was followed by a suggested decrease in the nasopharyngeal viral load in the nasopharynx and clinical improvement of the patient...

BACKGROUND: During the pandemic outbreak of the 2009 swine influenza (A(H1N1)pdm09), 32 fatal cases occurred in Norway and 19 of these were included in this study. OBJECTIVES: We characterised pulmonary changes in these fatal Norwegian cases. PATIENTS AND METHODS: Upon hospitalisation, detailed clinical information and specimens from the upper and lower respiratory pathways were collected. At post-mortem, lung tissue was collected, formalin-fixed and paraffin-embedded...

BACKGROUND: Serum antibody to influenza can be used to identify past exposure and measure current immune status. The two most common methods for measuring this are the hemagglutination inhibition assay (HI) and the viral neutralization assay (NT), which have not been systematically compared for a large number of influenza viruses. METHODS: A total of 151 study participants from near Guangzhou, China, were enrolled in 2009 and provided serum. HI and NT assays were performed for 12 historic and recently circulating strains of seasonal influenza A...

The aim of this review was to identify factors predicting actual or intended adherence to antivirals as treatment or prophylaxis for influenza. Literature from inception to March 2015 was systematically reviewed to find studies reporting predictors of adherence to antivirals and self-reported reasons for non-adherence to antivirals. Twenty-six studies were included in the review; twenty identified through the literature search and six through other means. Of these studies, 18 assessed predictors of actual adherence to antivirals, whereas eight assessed predictors of intended adherence...

BACKGROUND: Human rhinoviruses (HRV) cause a wide spectrum of disease, ranging from a mild influenza-like illness (ILI) to severe respiratory infection. Molecular epidemiological data are limited for HRV circulating in the Southern Hemisphere. OBJECTIVES: To identify the species and genotypes of HRV from clinical samples collected in Sydney, Australia, from 2006 to 2009. METHODS: Combined nose and throat swabs or nasopharyngeal aspirates collected from individuals with ILI were tested for HRV using real-time reverse-transcriptase polymerase chain reaction (RT-PCR)...

BACKGROUND: Influenza infection can result in severe disease with debilitating complications. Young children have the highest rate of influenza hospitalisations with various factors influencing influenza susceptibility and severity. OBJECTIVES: This study aimed to determine the disease burden and assess risk factors for severe hospitalised influenza in South Australian children under 5 years of age. METHODS: Influenza admissions to the tertiary paediatric hospital in South Australia from 2008 to 2012 were identified...

BACKGROUND: Influenza C is usually considered a minor cause of respiratory illness in humans with many infections being asymptomatic or clinically mild. Large outbreaks can occur periodically resulting in significant morbidity. OBJECTIVES: This study aimed at analyzing the available influenza C clinical samples from two widely separated states of Australia, collected over a 7-year period and to compare them with influenza C viruses detected in other parts of the world in recent years...

We report a whole-genome analysis of 19 influenza A(H1N1)pdm09 isolates from four Ugandan hospitals between 2009 and 2011. The isolates differed from the vaccine strain A/California/07/2009 by three amino acid substitutions P100S, S220T, and I338V in the hemagglutinin and by two amino acid substitutions V106I and N248D in the neuraminidase proteins with consistent mutations in all gene segments distinguishing isolates from the 2009/2010 to 2010/2011 seasons. Phylogenetic analysis showed low genetic evolution, with genetic distances of 0%-1...

AIM: The burden of disease in children attributable to influenza viruses is difficult to quantify given the similarity of symptoms caused by infection due to influenza and other viruses. This uncertainty impacts clinical decision-making and estimates of burden. We aimed to systematically review the literature to determine the proportion of healthy children presenting for health care with an acute respiratory illness (ARI) who have laboratory-confirmed seasonal influenza (PROSPERO ID#CRD42014013896)...